ASoC: add support for the Freescale P1022 DS reference board

The Freescale P1022 is a dual-core e500-based SOC with multimedia capabilities,
specifically the same SSI audio controller on the MPC8610.  The P1022 DS
reference board includes a P1022 and a Wolfson Microelectronics WM8776
codec.
Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/fsl/Kconfig

 config SND_MPC52xx_DMA
 	tristate
 
-# ASoC platform support for the Freescale MPC8610 SOC.  This compiles drivers
-# for the SSI and the Elo DMA controller.  You will still need to select
-# a platform driver and a codec driver.
-config SND_SOC_MPC8610
+# ASoC platform support for the Freescale PowerPC SOCs that have an SSI and
+# an Elo DMA controller, such as the MPC8610 and P1022.  You will still need to
+# select a platform driver and a codec driver.
+config SND_SOC_POWERPC_SSI
 	tristate
-	depends on MPC8610
+	depends on FSL_SOC
 
 config SND_SOC_MPC8610_HPCD
 	tristate "ALSA SoC support for the Freescale MPC8610 HPCD board"
 	# I2C is necessary for the CS4270 driver
 	depends on MPC8610_HPCD && I2C
-	select SND_SOC_MPC8610
+	select SND_SOC_POWERPC_SSI
 	select SND_SOC_CS4270
 	select SND_SOC_CS4270_VD33_ERRATA
 	default y if MPC8610_HPCD
 	help
 	  Say Y if you want to enable audio on the Freescale MPC8610 HPCD.
 
+config SND_SOC_P1022_DS
+	tristate "ALSA SoC support for the Freescale P1022 DS board"
+	# I2C is necessary for the WM8776 driver
+	depends on P1022_DS && I2C
+	select SND_SOC_POWERPC_SSI
+	select SND_SOC_WM8776
+	default y if P1022_DS
+	help
+	  Say Y if you want to enable audio on the Freescale P1022 DS board.
+	  This will also include the Wolfson Microelectronics WM8776 codec
+	  driver.
+
 config SND_SOC_MPC5200_I2S
 	tristate "Freescale MPC5200 PSC in I2S mode driver"
 	depends on PPC_MPC52xx && PPC_BESTCOMM

sound/soc/fsl/Makefile

@@ -2,10 +2,14 @@
 snd-soc-mpc8610-hpcd-objs := mpc8610_hpcd.o
 obj-$(CONFIG_SND_SOC_MPC8610_HPCD) += snd-soc-mpc8610-hpcd.o
 
-# MPC8610 Platform Support
+# P1022 DS Machine Support
+snd-soc-p1022-ds-objs := p1022_ds.o
+obj-$(CONFIG_SND_SOC_P1022_DS) += snd-soc-p1022-ds.o
+
+# Freescale PowerPC SSI/DMA Platform Support
 snd-soc-fsl-ssi-objs := fsl_ssi.o
 snd-soc-fsl-dma-objs := fsl_dma.o
-obj-$(CONFIG_SND_SOC_MPC8610) += snd-soc-fsl-ssi.o snd-soc-fsl-dma.o
+obj-$(CONFIG_SND_SOC_POWERPC_SSI) += snd-soc-fsl-ssi.o snd-soc-fsl-dma.o
 
 # MPC5200 Platform Support
 obj-$(CONFIG_SND_MPC52xx_DMA) += mpc5200_dma.o

sound/soc/fsl/p1022_ds.c

+/**
+ * Freescale P1022DS ALSA SoC Machine driver
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <sound/soc.h>
+#include <asm/fsl_guts.h>
+
+#include "fsl_dma.h"
+#include "fsl_ssi.h"
+
+/* P1022-specific PMUXCR and DMUXCR bit definitions */
+
+#define CCSR_GUTS_PMUXCR_UART0_I2C1_MASK	0x0001c000
+#define CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI	0x00010000
+#define CCSR_GUTS_PMUXCR_UART0_I2C1_SSI		0x00018000
+
+#define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK	0x00000c00
+#define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI	0x00000000
+
+#define CCSR_GUTS_DMUXCR_PAD	1	/* DMA controller/channel set to pad */
+#define CCSR_GUTS_DMUXCR_SSI	2	/* DMA controller/channel set to SSI */
+
+/*
+ * Set the DMACR register in the GUTS
+ *
+ * The DMACR register determines the source of initiated transfers for each
+ * channel on each DMA controller.  Rather than have a bunch of repetitive
+ * macros for the bit patterns, we just have a function that calculates
+ * them.
+ *
+ * guts: Pointer to GUTS structure
+ * co: The DMA controller (0 or 1)
+ * ch: The channel on the DMA controller (0, 1, 2, or 3)
+ * device: The device to set as the target (CCSR_GUTS_DMUXCR_xxx)
+ */
+static inline void guts_set_dmuxcr(struct ccsr_guts_85xx __iomem *guts,
+	unsigned int co, unsigned int ch, unsigned int device)
+{
+	unsigned int shift = 16 + (8 * (1 - co) + 2 * (3 - ch));
+
+	clrsetbits_be32(&guts->dmuxcr, 3 << shift, device << shift);
+}
+
+/* There's only one global utilities register */
+static phys_addr_t guts_phys;
+
+#define DAI_NAME_SIZE	32
+
+/**
+ * machine_data: machine-specific ASoC device data
+ *
+ * This structure contains data for a single sound platform device on an
+ * P1022 DS.  Some of the data is taken from the device tree.
+ */
+struct machine_data {
+	struct snd_soc_dai_link dai[2];
+	struct snd_soc_card card;
+	unsigned int dai_format;
+	unsigned int codec_clk_direction;
+	unsigned int cpu_clk_direction;
+	unsigned int clk_frequency;
+	unsigned int ssi_id;		/* 0 = SSI1, 1 = SSI2, etc */
+	unsigned int dma_id[2];		/* 0 = DMA1, 1 = DMA2, etc */
+	unsigned int dma_channel_id[2]; /* 0 = ch 0, 1 = ch 1, etc*/
+	char codec_name[DAI_NAME_SIZE];
+	char platform_name[2][DAI_NAME_SIZE]; /* One for each DMA channel */
+};
+
+/**
+ * p1022_ds_machine_probe: initialize the board
+ *
+ * This function is used to initialize the board-specific hardware.
+ *
+ * Here we program the DMACR and PMUXCR registers.
+ */
+static int p1022_ds_machine_probe(struct platform_device *sound_device)
+{
+	struct snd_soc_card *card = platform_get_drvdata(sound_device);
+	struct machine_data *mdata =
+		container_of(card, struct machine_data, card);
+	struct ccsr_guts_85xx __iomem *guts;
+
+	guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
+	if (!guts) {
+		dev_err(card->dev, "could not map global utilities\n");
+		return -ENOMEM;
+	}
+
+	/* Enable SSI Tx signal */
+	clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK,
+			CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI);
+
+	/* Enable SSI Rx signal */
+	clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK,
+			CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI);
+
+	/* Enable DMA Channel for SSI */
+	guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0],
+			CCSR_GUTS_DMUXCR_SSI);
+
+	guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1],
+			CCSR_GUTS_DMUXCR_SSI);
+
+	iounmap(guts);
+
+	return 0;
+}
+
+/**
+ * p1022_ds_startup: program the board with various hardware parameters
+ *
+ * This function takes board-specific information, like clock frequencies
+ * and serial data formats, and passes that information to the codec and
+ * transport drivers.
+ */
+static int p1022_ds_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct machine_data *mdata =
+		container_of(rtd->card, struct machine_data, card);
+	struct device *dev = rtd->card->dev;
+	int ret = 0;
+
+	/* Tell the codec driver what the serial protocol is. */
+	ret = snd_soc_dai_set_fmt(rtd->codec_dai, mdata->dai_format);
+	if (ret < 0) {
+		dev_err(dev, "could not set codec driver audio format\n");
+		return ret;
+	}
+
+	/*
+	 * Tell the codec driver what the MCLK frequency is, and whether it's
+	 * a slave or master.
+	 */
+	ret = snd_soc_dai_set_sysclk(rtd->codec_dai, 0, mdata->clk_frequency,
+				     mdata->codec_clk_direction);
+	if (ret < 0) {
+		dev_err(dev, "could not set codec driver clock params\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * p1022_ds_machine_remove: Remove the sound device
+ *
+ * This function is called to remove the sound device for one SSI.  We
+ * de-program the DMACR and PMUXCR register.
+ */
+static int p1022_ds_machine_remove(struct platform_device *sound_device)
+{
+	struct snd_soc_card *card = platform_get_drvdata(sound_device);
+	struct machine_data *mdata =
+		container_of(card, struct machine_data, card);
+	struct ccsr_guts_85xx __iomem *guts;
+
+	guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
+	if (!guts) {
+		dev_err(card->dev, "could not map global utilities\n");
+		return -ENOMEM;
+	}
+
+	/* Restore the signal routing */
+	clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK);
+	clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK);
+	guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0], 0);
+	guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1], 0);
+
+	iounmap(guts);
+
+	return 0;
+}
+
+/**
+ * p1022_ds_ops: ASoC machine driver operations
+ */
+static struct snd_soc_ops p1022_ds_ops = {
+	.startup = p1022_ds_startup,
+};
+
+/**
+ * get_node_by_phandle_name - get a node by its phandle name
+ *
+ * This function takes a node, the name of a property in that node, and a
+ * compatible string.  Assuming the property is a phandle to another node,
+ * it returns that node, (optionally) if that node is compatible.
+ *
+ * If the property is not a phandle, or the node it points to is not compatible
+ * with the specific string, then NULL is returned.
+ */
+static struct device_node *get_node_by_phandle_name(struct device_node *np,
+	const char *name, const char *compatible)
+{
+	np = of_parse_phandle(np, name, 0);
+	if (!np)
+		return NULL;
+
+	if (!of_device_is_compatible(np, compatible)) {
+		of_node_put(np);
+		return NULL;
+	}
+
+	return np;
+}
+
+/**
+ * get_parent_cell_index -- return the cell-index of the parent of a node
+ *
+ * Return the value of the cell-index property of the parent of the given
+ * node.  This is used for DMA channel nodes that need to know the DMA ID
+ * of the controller they are on.
+ */
+static int get_parent_cell_index(struct device_node *np)
+{
+	struct device_node *parent = of_get_parent(np);
+	const u32 *iprop;
+	int ret = -1;
+
+	if (!parent)
+		return -1;
+
+	iprop = of_get_property(parent, "cell-index", NULL);
+	if (iprop)
+		ret = *iprop;
+
+	of_node_put(parent);
+
+	return ret;
+}
+
+/**
+ * codec_node_dev_name - determine the dev_name for a codec node
+ *
+ * This function determines the dev_name for an I2C node.  This is the name
+ * that would be returned by dev_name() if this device_node were part of a
+ * 'struct device'  It's ugly and hackish, but it works.
+ *
+ * The dev_name for such devices include the bus number and I2C address. For
+ * example, "cs4270-codec.0-004f".
+ */
+static int codec_node_dev_name(struct device_node *np, char *buf, size_t len)
+{
+	const u32 *iprop;
+	int bus, addr;
+	char temp[DAI_NAME_SIZE];
+
+	of_modalias_node(np, temp, DAI_NAME_SIZE);
+
+	iprop = of_get_property(np, "reg", NULL);
+	if (!iprop)
+		return -EINVAL;
+
+	addr = *iprop;
+
+	bus = get_parent_cell_index(np);
+	if (bus < 0)
+		return bus;
+
+	snprintf(buf, len, "%s-codec.%u-%04x", temp, bus, addr);
+
+	return 0;
+}
+
+static int get_dma_channel(struct device_node *ssi_np,
+			   const char *compatible,
+			   struct snd_soc_dai_link *dai,
+			   unsigned int *dma_channel_id,
+			   unsigned int *dma_id)
+{
+	struct resource res;
+	struct device_node *dma_channel_np;
+	const u32 *iprop;
+	int ret;
+
+	dma_channel_np = get_node_by_phandle_name(ssi_np, compatible,
+						  "fsl,ssi-dma-channel");
+	if (!dma_channel_np)
+		return -EINVAL;
+
+	/* Determine the dev_name for the device_node.  This code mimics the
+	 * behavior of of_device_make_bus_id(). We need this because ASoC uses
+	 * the dev_name() of the device to match the platform (DMA) device with
+	 * the CPU (SSI) device.  It's all ugly and hackish, but it works (for
+	 * now).
+	 *
+	 * dai->platform name should already point to an allocated buffer.
+	 */
+	ret = of_address_to_resource(dma_channel_np, 0, &res);
+	if (ret)
+		return ret;
+	snprintf((char *)dai->platform_name, DAI_NAME_SIZE, "%llx.%s",
+		 (unsigned long long) res.start, dma_channel_np->name);
+
+	iprop = of_get_property(dma_channel_np, "cell-index", NULL);
+	if (!iprop) {
+		of_node_put(dma_channel_np);
+		return -EINVAL;
+	}
+
+	*dma_channel_id = *iprop;
+	*dma_id = get_parent_cell_index(dma_channel_np);
+	of_node_put(dma_channel_np);
+
+	return 0;
+}
+
+/**
+ * p1022_ds_probe: platform probe function for the machine driver
+ *
+ * Although this is a machine driver, the SSI node is the "master" node with
+ * respect to audio hardware connections.  Therefore, we create a new ASoC
+ * device for each new SSI node that has a codec attached.
+ */
+static int p1022_ds_probe(struct platform_device *pdev)
+{
+	struct device *dev = pdev->dev.parent;
+	/* ssi_pdev is the platform device for the SSI node that probed us */
+	struct platform_device *ssi_pdev =
+		container_of(dev, struct platform_device, dev);
+	struct device_node *np = ssi_pdev->dev.of_node;
+	struct device_node *codec_np = NULL;
+	struct platform_device *sound_device = NULL;
+	struct machine_data *mdata;
+	int ret = -ENODEV;
+	const char *sprop;
+	const u32 *iprop;
+
+	/* Find the codec node for this SSI. */
+	codec_np = of_parse_phandle(np, "codec-handle", 0);
+	if (!codec_np) {
+		dev_err(dev, "could not find codec node\n");
+		return -EINVAL;
+	}
+
+	mdata = kzalloc(sizeof(struct machine_data), GFP_KERNEL);
+	if (!mdata)
+		return -ENOMEM;
+
+	mdata->dai[0].cpu_dai_name = dev_name(&ssi_pdev->dev);
+	mdata->dai[0].ops = &p1022_ds_ops;
+
+	/* Determine the codec name, it will be used as the codec DAI name */
+	ret = codec_node_dev_name(codec_np, mdata->codec_name, DAI_NAME_SIZE);
+	if (ret) {
+		dev_err(&pdev->dev, "invalid codec node %s\n",
+			codec_np->full_name);
+		ret = -EINVAL;
+		goto error;
+	}
+	mdata->dai[0].codec_name = mdata->codec_name;
+
+	/* We register two DAIs per SSI, one for playback and the other for
+	 * capture.  We support codecs that have separate DAIs for both playback
+	 * and capture.
+	 */
+	memcpy(&mdata->dai[1], &mdata->dai[0], sizeof(struct snd_soc_dai_link));
+
+	/* The DAI names from the codec (snd_soc_dai_driver.name) */
+	mdata->dai[0].codec_dai_name = "wm8776-hifi-playback";
+	mdata->dai[1].codec_dai_name = "wm8776-hifi-capture";
+
+	/* Get the device ID */
+	iprop = of_get_property(np, "cell-index", NULL);
+	if (!iprop) {
+		dev_err(&pdev->dev, "cell-index property not found\n");
+		ret = -EINVAL;
+		goto error;
+	}
+	mdata->ssi_id = *iprop;
+
+	/* Get the serial format and clock direction. */
+	sprop = of_get_property(np, "fsl,mode", NULL);
+	if (!sprop) {
+		dev_err(&pdev->dev, "fsl,mode property not found\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	if (strcasecmp(sprop, "i2s-slave") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_I2S;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
+
+		/* In i2s-slave mode, the codec has its own clock source, so we
+		 * need to get the frequency from the device tree and pass it to
+		 * the codec driver.
+		 */
+		iprop = of_get_property(codec_np, "clock-frequency", NULL);
+		if (!iprop || !*iprop) {
+			dev_err(&pdev->dev, "codec bus-frequency "
+				"property is missing or invalid\n");
+			ret = -EINVAL;
+			goto error;
+		}
+		mdata->clk_frequency = *iprop;
+	} else if (strcasecmp(sprop, "i2s-master") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_I2S;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
+	} else if (strcasecmp(sprop, "lj-slave") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
+	} else if (strcasecmp(sprop, "lj-master") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
+	} else if (strcasecmp(sprop, "rj-slave") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
+	} else if (strcasecmp(sprop, "rj-master") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
+	} else if (strcasecmp(sprop, "ac97-slave") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_AC97;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
+	} else if (strcasecmp(sprop, "ac97-master") == 0) {
+		mdata->dai_format = SND_SOC_DAIFMT_AC97;
+		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
+		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
+	} else {
+		dev_err(&pdev->dev,
+			"unrecognized fsl,mode property '%s'\n", sprop);
+		ret = -EINVAL;
+		goto error;
+	}
+
+	if (!mdata->clk_frequency) {
+		dev_err(&pdev->dev, "unknown clock frequency\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	/* Find the playback DMA channel to use. */
+	mdata->dai[0].platform_name = mdata->platform_name[0];
+	ret = get_dma_channel(np, "fsl,playback-dma", &mdata->dai[0],
+			      &mdata->dma_channel_id[0],
+			      &mdata->dma_id[0]);
+	if (ret) {
+		dev_err(&pdev->dev, "missing/invalid playback DMA phandle\n");
+		goto error;
+	}
+
+	/* Find the capture DMA channel to use. */
+	mdata->dai[1].platform_name = mdata->platform_name[1];
+	ret = get_dma_channel(np, "fsl,capture-dma", &mdata->dai[1],
+			      &mdata->dma_channel_id[1],
+			      &mdata->dma_id[1]);
+	if (ret) {
+		dev_err(&pdev->dev, "missing/invalid capture DMA phandle\n");
+		goto error;
+	}
+
+	/* Initialize our DAI data structure.  */
+	mdata->dai[0].stream_name = "playback";
+	mdata->dai[1].stream_name = "capture";
+	mdata->dai[0].name = mdata->dai[0].stream_name;
+	mdata->dai[1].name = mdata->dai[1].stream_name;
+
+	mdata->card.probe = p1022_ds_machine_probe;
+	mdata->card.remove = p1022_ds_machine_remove;
+	mdata->card.name = pdev->name; /* The platform driver name */
+	mdata->card.num_links = 2;
+	mdata->card.dai_link = mdata->dai;
+
+	/* Allocate a new audio platform device structure */
+	sound_device = platform_device_alloc("soc-audio", -1);
+	if (!sound_device) {
+		dev_err(&pdev->dev, "platform device alloc failed\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/* Associate the card data with the sound device */
+	platform_set_drvdata(sound_device, &mdata->card);
+
+	/* Register with ASoC */
+	ret = platform_device_add(sound_device);
+	if (ret) {
+		dev_err(&pdev->dev, "platform device add failed\n");
+		goto error;
+	}
+
+	of_node_put(codec_np);
+
+	return 0;
+
+error:
+	of_node_put(codec_np);
+
+	if (sound_device)
+		platform_device_unregister(sound_device);
+
+	kfree(mdata);
+
+	return ret;
+}
+
+/**
+ * p1022_ds_remove: remove the platform device
+ *
+ * This function is called when the platform device is removed.
+ */
+static int __devexit p1022_ds_remove(struct platform_device *pdev)
+{
+	struct platform_device *sound_device = dev_get_drvdata(&pdev->dev);
+	struct snd_soc_card *card = platform_get_drvdata(sound_device);
+	struct machine_data *mdata =
+		container_of(card, struct machine_data, card);
+
+	platform_device_unregister(sound_device);
+
+	kfree(mdata);
+	sound_device->dev.platform_data = NULL;
+
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver p1022_ds_driver = {
+	.probe = p1022_ds_probe,
+	.remove = __devexit_p(p1022_ds_remove),
+	.driver = {
+		/* The name must match the 'model' property in the device tree,
+		 * in lowercase letters, but only the part after that last
+		 * comma.  This is because some model properties have a "fsl,"
+		 * prefix.
+		 */
+		.name = "snd-soc-p1022",
+		.owner = THIS_MODULE,
+	},
+};
+
+/**
+ * p1022_ds_init: machine driver initialization.
+ *
+ * This function is called when this module is loaded.
+ */
+static int __init p1022_ds_init(void)
+{
+	struct device_node *guts_np;
+	struct resource res;
+
+	pr_info("Freescale P1022 DS ALSA SoC machine driver\n");
+
+	/* Get the physical address of the global utilities registers */
+	guts_np = of_find_compatible_node(NULL, NULL, "fsl,p1022-guts");
+	if (of_address_to_resource(guts_np, 0, &res)) {
+		pr_err("p1022-ds: missing/invalid global utilities node\n");
+		return -EINVAL;
+	}
+	guts_phys = res.start;
+	of_node_put(guts_np);
+
+	return platform_driver_register(&p1022_ds_driver);
+}
+
+/**
+ * p1022_ds_exit: machine driver exit
+ *
+ * This function is called when this driver is unloaded.
+ */
+static void __exit p1022_ds_exit(void)
+{
+	platform_driver_unregister(&p1022_ds_driver);
+}
+
+module_init(p1022_ds_init);
+module_exit(p1022_ds_exit);
+
+MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
+MODULE_DESCRIPTION("Freescale P1022 DS ALSA SoC machine driver");
+MODULE_LICENSE("GPL v2");